There can be a need in fluid control valves to fine-tune the dimensions of components of the valve, or of sub-assemblies of components of the valve. This can be due to potential variations in the dimensions of various sub-component parts, which may be the result of natural variance or inaccuracies in the manufacturing processes of components of the valve or its sub-assemblies. It is therefore important to be able to fine-tune dimensions of an assembly during the assembly process, to ensure that the correct sub-assembly dimensions, tolerances and/or clearances are achieved in the final valve assembly.
One way to adjust the dimension of a component is to use a threaded connection to achieve variations in longitudinal dimensions of a sub-assembly, by rotation of the components of the sub-assembly relative to one another, and to optionally use a glue to lock the two sub-components at a chosen relative position.
However, there are various problems with using a threaded connection and/or glue. Using a threaded connection has associated production costs and introduces mechanical gaps into the sub-assembly. These mechanical gaps may be detrimental to the valve performance, for example if the sub-component parts are a shaft and a plunger of a solenoid valve, using a threaded connection to connect the shaft and the plunger may reduce the magnetic performance of the solenoid valve.
Various problems can occur when using a glue to connect sub-component parts. One problem can be that the glue may limit the potential uses of the valve, as the glue may not be suited to coming into contact with an incompatible liquid, for example a corrosive liquid or any liquid that may react with or dissolve the glue or cause any chemical from the glue to leach into the liquid. Another problem with using a glue to secure two sub-component parts can be that the glue takes time to set, which may increase the production time for the valve and causes associated costs. Another problem with using a glue to secure two sub-component parts is that the glue's quantity may not be easily controlled. Another problem with using a glue to secure sub-component parts can be that the method of using a glue to attach the two sub-components may be susceptible to errors both in the accuracy of the dimension of the component, and the accuracy of the adhesive property of the glue. For example, the chemical composition and setting time of the glue may need to be controlled in order to give the required adhesive property. The setting reaction of the glue may be susceptible small errors caused by variations in temperature, atmospheric conditions and manufacturing contaminations. Small errors in the glue setting reaction may affect the setting time, which in turn can reduce the ability to accurately control the final dimension of the component since movement could occur during setting of the glue.
There is therefore a need for improved means to for attaching valve sub-components to one another.